
<PAGE>   1
 EXHIBIT 12.1

                           AVALONBAY COMMUNITIES, INC.
   RATIOS OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS

<TABLE>
<CAPTION>


                                                                 Three Months                Year                  Year
                                                                     Ended                   Ended                 Ended
                                                                   March 31,             December 31,          December 31,
                                                                     2000                    1999                  1998
                                                                 ------------            ------------          ------------
<S>                                                             <C>                    <C>                    <C>

Net Operating Income                                             $   47,172              $    172,276          $    123,535

(Less) Nonrecurring item:

           Gain on sale                                          $   (7,910)             $    (47,093)         $    (25,270)
           Non-recurring charges                                          -                    16,782                   -

 (Plus) Extraordinary item:

                 Unamortized loan fee write-off                  $        -              $         -           $        245

 (Plus) Fixed charges:
             Portion of rents representative
                  of the interest factor                         $      110              $        526          $        293
             Interest expense                                        20,067                    74,699                54,650
             Interest capitalized                                     3,494                    21,888                14,724
             Debt cost amortization                                     677                     2,624                 2,068
             Preferred dividend                                       9,945                    39,779                28,132

                                                                   ------------            ----------            ----------

                      Total fixed charges (1)                    $   34,293              $    139,516          $     99,867

 (Less):

                 Interest capitalized                            $    3,494              $     21,888          $     14,724

                 Preferred dividend                                   9,945                    39,779                28,132

 Adjusted earnings (2)                                           $   60,116              $    219,814          $    155,521
                                                                   ------------            ----------            ----------

Ratio (2 divided by 1)                                                 1.75                      1.58                  1.56
                                                                   ------------            ----------            ----------




                                                                      Year                  Year                  Year
                                                                      Ended                 Ended                 Ended
                                                                  December 31,          December 31,          December 31,
                                                                      1997                  1996                  1995
                                                                  ------------          ------------          ------------
<S>                                                              <C>                   <C>                   <C>

Net Operating Income                                              $     64,916          $     51,651          $     30,937

(Less) Nonrecurring item:

           Gain on sale                                           $       (677)         $     (7,850)         $          -
           Non-recurring charges                                           -                     -                       -

 (Plus) Extraordinary item:

                 Unamortized loan fee write-off                   $      1,183          $      2,356          $      1,158

 (Plus) Fixed charges:
             Portion of rents representative
                  of the interest factor                          $        172          $        150          $        117
             Interest expense                                           16,977                 9,545                11,056
             Interest capitalized                                        9,024                12,883                 6,004
             Debt cost amortization                                        700                 1,842                 1,869
             Preferred dividend                                         19,656                10,422                     -

                                                                    ----------            ----------            ----------

                      Total fixed charges (1)                     $     46,529          $     34,842           $    19,046

 (Less):

                 Interest capitalized                             $      9,024          $     12,883           $     6,004

                 Preferred dividend                                     19,656                10,422                     -

 Adjusted earnings (2)                                            $     83,271          $     57,694           $    45,137
                                                                    ----------            ----------            ----------

Ratio (2 divided by 1)                                                    1.79                  1.66                  2.37
                                                                    ----------            ----------            ----------

</TABLE>



<PAGE>   2


 EXHIBIT 12.1 (CONTINUED)

                           AVALONBAY COMMUNITIES, INC.
                       RATIOS OF EARNINGS TO FIXED CHARGES


<TABLE>
<CAPTION>


                                                                 Three Months                Year                  Year
                                                                     Ended                   Ended                 Ended
                                                                   March 31,             December 31,          December 31,
                                                                     2000                    1999                  1998
                                                                  ------------            ------------          ------------
<S>                                                             <C>                      <C>                   <C>

 Net Operating Income                                            $      47,172            $    172,276          $    123,535

 (Less) Nonrecurring item:
            Gain on sale                                         $      (7,910)           $    (47,093)         $    (25,270)
            Non-recurring charges                                          -                    16,782                  -

 (Plus) Extraordinary item:
             Unamortized loan fee write-off                      $         -              $       -             $        245

 (Plus) Fixed charges:
            Portion of rents representative
                 of the interest factor                          $         110            $        526          $        293
            Interest expense                                            20,067                  74,699                54,650
            Interest capitalized                                         3,494                  21,888                14,724
            Debt cost amortization                                         677                   2,624                 2,068
                                                                  ------------            ------------          ------------

              Total fixed charges (1)                            $      24,348            $     99,737          $     71,735

 (Less):

                 Interest capitalized                            $       3,494            $     21,888          $     14,724

 Adjusted earnings (2)                                           $      60,116            $    219,814          $    155,521
                                                                  ------------             -----------           -----------

 Ratio (2 divided by 1)                                                   2.47                    2.20                  2.17
                                                                  ============             ===========           ===========




                                                                        Year                  Year                  Year
                                                                        Ended                 Ended                 Ended
                                                                    December 31,          December 31,          December 31,
                                                                        1997                  1996                  1995
                                                                     ------------          ------------          ------------
<S>                                                                 <C>                   <C>                   <C>

 Net Operating Income                                                $     64,916          $     51,651          $     30,937

 (Less) Nonrecurring item:
            Gain on sale                                             $       (677)         $     (7,850)                    -
            Non-recurring charges                                             -                     -                       -

 (Plus) Extraordinary item:
             Unamortized loan fee write-off                          $      1,183          $      2,356          $      1,158

 (Plus) Fixed charges:
            Portion of rents representative
                 of the interest factor                              $        172          $        150          $        117
            Interest expense                                               16,977                 9,545                11,056
            Interest capitalized                                            9,024                12,883                 6,004
            Debt cost amortization                                            700                 1,842                 1,869
                                                                     ------------          ------------          ------------

              Total fixed charges (1)                                $     26,873          $     24,420          $     19,046

 (Less):

                 Interest capitalized                                $      9,024          $     12,883          $      6,004

 Adjusted earnings (2)                                               $     83,271          $     57,694          $     45,137
                                                                      -----------           -----------           -----------

 Ratio (2 divided by 1)                                                      3.10                  2.36                  2.37
                                                                      ===========           ===========           ===========

</TABLE>


